Toward the end-20TH and early 21ST century Homo “sapiens” is realizing its carbon emissions, totaling over 300 billion tons (GtC) since 1750, and other forms of interference with the global natural system, are leading to sharp departure from the conditions which allowed its success on the planet, including rapid warming of the atmosphere to near +1.3 degrees C (partly masked by emitted aerosols) above pre-industrial levels and acidification of the oceans (decrease in pH by near-0.1) ( http://en.wikipedia.org/wiki/File:AYool_GLODAP_del_pH.png ), endangering the marine food chain.

Human inertia is paramount. Politics-as-usual and economics-as-usual can not argue with the laws of physics and chemistry, nor can they stop the climate from tracking toward increasingly dangerous states, likely approaching a tipping point of no return.

A principal think tank is the American Enterprise Institute (AEI), more than 20 of whose staff have worked as consultants to the Bush administration. The AEI has received more than $1.6 million from ExxonMobil and is offering scientists cash grants of $10,000 if they were prepared to dispute reports by the Intergovernmental Panel for Climate Change (IPCC) ( http://www.guardian.co.uk /environment/2007/feb/02/frontpagenews. climatechange ).

Some "skeptics" appear to confuse, or pretend to confuse, the weather with the climate, misunderstand meaning of terms such as “average” or “trend”, hinging their arguments on transient cooling events. Lately, based on the La Nina cooling phase since 2007, some claim global cooling ( http://www.worldclimatereport.com /index.php/2007/03/16/the-coming-global-cooling/) (would have been nice).

There are those who say climate has always changed, and is not of anthropogenic origin ( http://www.smedg.org.au/plimer0701.html ) (which overlooks the consequences of emission of some 300 gigaton of carbon since the down of the industrial age).

Publishing in politically friendly media provides a golden opportunity to gain public exposure and air grudges against science and scientists. A hallmark of climate change skeptics is the dissemination of doubt (“doubt is our product”) ( http://www.desmogblog.com/directory/vocabulary/4067 ) and a reluctance to engage in direct public discussions with climate scientists.

The legal status of disinformation campaigns aimed at the promotion of substances of proven fatal consequences, such as ozone-destroying CFCs, or the release of CO2 to levels over 350 ppm ( http://www.columbia.edu/~jeh1/2008/TargetCO2_ 20080407.pdf ), may yet prove to be the Achilles heel of global civilization.

Andrew Glikson
Earth/paleo-climate scientist
Australian National University